GSOC 2025: Advanced vector editing tool modes

[4adex]

Hi there,
I'm Adesh Gupta (@4adex ), and I’ll be working with Graphite as a GSoC 2025 contributor. My project is titled "Advanced Vector Editing Tool Modes", and it focuses on improving the vector editing experience in the Graphite editor by introducing new and state of the art tool features and extending existing tools to support vector meshes.

Introduction

The aim of this project is to add Segment Editing Mode and Region Editing Mode to the Path Tool, allowing more granular and flexible manipulation of vector elements. These modes will support individual and combined selections, with features like lasso/bounding-box selection, segment bending, region dragging, and more.

Alongside this, I will be refactoring the Pen and Path Tools to better support vector meshes. Current vector tools are limited to paths and struggle with shared anchors or overlapping regions. My work will enable operations such as merging anchors, gluing/peeling segments, and creating segments between selected anchors—expanding the editing capabilities significantly.

Benefits

• Enables precise control with segment and region selection modes, improving the overall editing workflow.
• Adds proper vector mesh support—anchors and segments can now be shared across multiple regions.
• Introduces topological operations like merging anchors, gluing/peeling segments, and merging regions directly in the editor.
• Refactors and extends the current tool architecture, making the Path and Pen tools more versatile and future-ready.

Deliverables

• Segment and Region Editing Modes with full UI and selection support
• Refactored Pen and Path Tools to support vector mesh editing
• New tooling operations including:
  • Scissor Tool for breaking segments at specific points
  • Knife Tool (stretch goal) for hand-drawn region splits using curve fitting
  • Segment creation, merging, separating, and region manipulation operations
• Updated overlay visuals and tool behavior based on selected editing modes

Final Report

• 15 merged PRs
• 12 closed issues
• 4,785 added lines, 1,313 removed lines

The project is overall a success, enhancing the vector editing tools, introducing new modes for more immersive and precise vector editing, improving existing features, and adding support for vector mesh editing by pen and path tool. Path tool now has a new segment editing mode which is equivalent of blender's "Edge Select Mode", it allows the user to precisely manipulate vector segments, without doing redundant task with anchor points. Both path tool and pen tool are now debugged for vector mesh support, and additional features have been incorporated for vector meshes.

The next step for the project will be to first finalize the design of remaining features implemented and merge all of them one by one, find the existing bugs and prune them. Thereafter continue with addition of new path editing modes such as knife tool, which is mentioned as a stretch task in the proposal. I will also be working upon contributing in implementing newly designed context menus. I am excited to continue with my contributions in the project, helping it to achieve all of its future goals. This GSoC project was a very good experience, collaborating with other skilled contributors, working on a large and good codebase, and designing new features for Graphite.

Path Tool: Segment editing mode #2712

This is one of the major contributions done in this project, which is introducing a "segment editing mode" similar to blender's "Edge Select Mode". This means user can perform all of the operations that were done on points now on segments also. These operations include - selection, dragging, deleting, etc. Additionally features such as "insert point on segment" and "molding segments" were also added for improved user experience. One of the important tasks was to define the SelectedLayerState and to expose relevant methods to be used inside tools, it only used to store the selected_points, but now it also supports selected_segments.

Selection had different challenges, "click to select" needed its own overlay to visually define which segments are selected and which segment is being hovered over. Box selection and lasso selection also had design challenges. Touched and enclosed selection modes needed their own implementations (https://pomax.github.io/bezierinfo/#boundingbox) to decide whether a bezier curve is partially inside or completely inside a polygon or not.

Delete segment was done as a modification to the vector, G/R/S feature support is also added to the segments. One can select a segment, pan it with G, rotate it with R and scale it with S.

Path Tool: Improved overlays and dynamic contextual hints #2860

This came as a byproduct of working on the segment editing feature, the partially transparent overlay on hover provides dynamic context to the user and is very intuitive. Segments and points both have these semi transparent hover overlays now.
Hints in the hints bar are now dynamic, an operation is hinted only when it can be performed according to current states. This also solved many TODO's related to hints in the path tool code.

Pen and Path Tool: Improving support for vector mesh editing

Vector meshes is an experimental feature in Graphite (similar to vector networks in Figma), which allows the users to draw mesh of vector paths, without being bound to the traditional SVG constraints. This project aimed to improve tooling support for making and editing vector meshes.

Debugging existing features #2695

In traditional vector programs, a single anchor point is not expected to have more than two segments connected, some features of Graphite were also implemented having that assumption. These made tools to break when used with vector meshes, I found such edge cases that were present in pen and path tool and re-implemented the logic in a safer way which works for more general set of vector meshes.

Pen tool can start and end in between segments #2692

This was a quality of life improvement which I proposed in my proposal, and has been implemented and merged. When drawing with the pen tool, if the user want to break the segment at a point, and attach the incoming segment there, he/she needs to switch to path tool and then switch back to the pen tool for doing the same. The new improved pen tool allows you to start drawing a new segment from a point on the segment, and also end the incoming segment on a new point on the segment.

Path Tool: Cut, Copy, Paste, Duplicate for vector data #2812

Path Tool currently did not supported copying and pasting geometry (points, segments). This was a feature which was necessary to extend the usability of Graphite as a vector editing program. It was a priority issue which was not initially part of the project, but it aligned very much with the direction and scope, hence was given to me by my mentor. The most challenging task was to decide which data structure is going to be serialized, and using the geometry information in deserialized data to modify the vector during paste.

Miscellaneous Contributions

These additional contributions, while not part of the project's primary objectives, closely aligned with the goal of enhancing vector editing capabilities in Graphite. They further improved the user experience and expanded the toolset available for vector manipulation.

Point Sliding Feature #2682

Before starting off the project I was contributing on Graphite to complete #1870. During the coding period I worked on completing "Sliding Point" feature which later also got a followup PR for shifting the behavior from Ctrl Shift drag to, G``G because it will be equivalent to blender's move vertex along segment (#2913)

Double Click to alter layer selection #2794

Path tool was able to work on multiple layers and layers can be added into the selection with a single click, but this also lead to wrongly clicking layers. This PR attempted to improve the layer switching and selection using double clicking (more details related to design in the PR).

Make node chooser auto filter by layer input #2841

This was a small quality of life improvement which was needed before open sauce, this uses the existing filtering logic based on node type of the incoming node. The main challenge was to determine the node type of the rightmost node which is connected to the layer.

Make Path Node Editable Button

This feature is also a small user experience improvement, which allows users to insert a new Path node at the end of steam of nodes, just before the layer. It allows the user to make checkpoints of the vector modifications done (having some modifications in one node, rest in other and so on). Adding node manually always makes that possible, but this UI button makes it much more accessible.

Remove existing bugs in the path tool #3070

Many of the recent developments in the path tool also introduces some regressions which needed to be pruned. This PR was an attempt to collect all those regressions which were high priority and remove them covering all the edge cases.

New Actions

Actions are similar to blender context menu options, things which can be done in one click and perform some change into the vector. Some new actions have been implemented which will facilitate vector mesh editing and vector editing in general by the path tool. These actions include -

Merge Point #2966

Attempts to join the points which are nearby in the vector meshes of selected layers. Finds the points which are close within a certain threshold, if they are, a new point is added at their mass center, old points are deleted, and all the connections are rebuilt. Hence the merged point is at the centroid of all old points (which were close under threshold).

Gluing Segments #3038

Attempts to joint the segments which are close to each other in the selected layers. The initial prototype has been implemented in the coding period and needs to be refined further (under process).

merge.segments.feat.webm

Peel and Separate Segment #3038

Separating and peeling a selected segment. Separate segment had a challenge of deciding at which newer segment the old connection will be placed, in current version that is managed by comparing the dot product of incoming handle with perpendicular vector of the segment. Initial prototype has been implemented in the coding period and is under the process of definition.

Notes about region editing mode and other tasks

• I also mentioned region editing mode in the proposal but it was discussed with the mentors that it is not the current need of Graphite, also hovering and precisely selecting regions need some further apis for vector meshes which were currently under development hence a blocker for region editing mode in vector meshes.
• The scissor tool was very similar to existing "cut on anchor" feature and "insert point on segment" feature hence it was redundant to add it as a separate tool.
• Join feature (using Ctrl + J) is already present which I was not aware about when making the proposal, hence that is also not implemented separately but vector mesh support has been added to it.
• I will continue to contribute on Graphite, which will also include implementing the knife tool (mentioned as stretch task in proposal).

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On a final note, contributing to a project like Graphite has been an incredibly rewarding and educational experience. Thank for providing this opportunity!

[4adex]

Week 1:

• Worked on finding the best approximation of two connected G1 continuous bezier curves by a single one, for path tool point sliding feature.
• Finished the implementation of sliding point with path tool. (Add anchor sliding along adjacent segments in the Path tool #2682)
• Finished the implementation of task 1 and task 2 according to proposal. (Add Pen tool support for starting and ending segment drawing on existing path edges for vector meshes #2692)
• Listed down the tasks for improving current tooling support for vector meshes. (Tracking Issue: Improving editing support for vector meshes #2695)
• Fixed a bug from previous feature (Fix the Path tool's segment insertion line overlay having hysteresis with distance away from the cursor #2677)

[4adex]

Week 2:

• Worked on segment editing mode feature of the path tool.
• implemented selection and storage of selected segments in SelectedLayerState
• Shift + click to select and deselect segments
• overlays for selgment selection mode (highlighting the segment hovering on + displaying selected segments)
• box and lasso selection of segments

2025-06-11.18-42-20.mp4

2025-06-13.01-20-03.mp4

2025-06-14.00-53-36.mp4

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Week 3:

• Touched and Enclosed selection modes for Box selection of segments.
• Added support for delete segments by pressing delete.
• Shift select is now compatible in between of segment and point selection.
• Added G/R/S support for selected segments.
• Modifier + click selected segment to mold the segment.
• Dynamic hints, hints related to molding segment/ adding a point on segment/ deleting a segment only become visible when your pointer is actually close to the segment. Ended up with segment editing mode and it is up for review.
• This completes the segment select mode feat (Add segment editing mode to the Path tool #2712)
• Completed the first task of (Improve Path tool layer and point selection behavior #2716)
• Discussed a probable approach for vector mesh rendering with @indierusty

[4adex]

Week 4:

• Fixed some bugs in Segment editing mode. (Add segment editing mode to the Path tool #2712) merged now, needs a follow up PR for additional features (as mentioned in discussion of same PR).
• Worked and completed Improve Path tool layer selection behavior using double-click instead of single-click #2794
• Worked and completed Add the re-fit on delete feature to the Path tool #2768 for the issue Deleting (dissolving) a point should scale its adjacent handles to minimize curvature change #2651.
• Started working on Copying and pasting geometry while in the Path tool #2744

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Week 5:

• Implemented the geometry copy and paste in the path tool. Including duplicate and cut modes also. ⁠Add copy/cut/paste/duplicate functionality for path geometry #2812, with specific considerations as asked in https://discord.com/channels/731730685944922173/1319602515758682132/1389813613602275408
• Did corrections in path tool layer and point selection behavior. Merged now (Improve Path tool layer and point selection behavior #2716).

[4adex]

Week 6:

• Code cleanup for molding segments feat (Clean up the Path tool's FSM to move segment molding state into the dragging state #2835)
• Fix segment drag molding work with linear segments (Make the Path tool's segment drag molding work with linear segments #2838)
• UX Improvement of showing only compatible nodes when adding nodes from UI buttons (Make the node chooser auto filter by layer input type when applicable #2841)
• Done with initial work on followup PR of segment editing mode (Improve the Path tool's segment editing mode and make hovering manipulators react contextually #2860)

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Week 7:

• Completed the remaining part of Make the node chooser auto filter by layer input type when applicable #2841
• Worked on first round of review of Improve the Path tool's segment editing mode and make hovering manipulators react contextually #2860
• Completed Add "Make Path Editable" buttons in the Path tool control bar and Layer menu #2900
• Completed Remap Path tool point sliding to G G #2913 closing Point sliding with G G #2715

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Week 8:

• Completed the tracking issue Tracking Issue: Improving editing support for vector meshes #2695
• Did improvements as asked in reviews in Improve the Path tool's segment editing mode and make hovering manipulators react contextually #2860 and Remap Path tool point sliding to G G #2913
• Starting with point merging feat in path tool.

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Week 9:

• Partly fixed Partly fix when the "Make Path Editable" button is shown as enabled #2968
• Worked on Add a Path tool action to destructively merge nearby points by distance #2966 (hints and dynamic disabling of button left)
• Started some work on gluing segments feature.

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Week 10:

• Completed merge points feat Add a Path tool action to destructively merge nearby points by distance #2966
• Implemented gluing segments feature Remap Path tool point sliding to G G #2913
• Repaired Point sliding GG PR, which broke after latest merge (Remap Path tool point sliding to G G #2913)

Screencast from 11-08-25 09:01:13 AM IST.webm (merge points feat)
Screencast from 10-08-25 03:32:27 PM IST.webm (gluing segments feat)

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Week 11:

• Was figuring out the cause for regression in shallow select tool and fixed it (Fix regression in shallow select #3050)
• Did a complete evaluation of tools looking for regressions that might have came up due to new Defer system, reported a few (not actually related to that issue only)
• Was working on separating and peeling segments feature for path tool.

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Week 12:

Solved these following minor regressions in the path tool (PR Open #3070) -

• Ctrl A in path tool, should select all segments also if segment select mode is enabled. (https://discord.com/channels/731730685944922173/881073965047636018/1406378997830521102)
• The overlay of hovering segment remains after deleting the segment in segment select mode. (https://discord.com/channels/731730685944922173/881073965047636018/1406376716657754263)
• Fix the flawed implementation of select_points_by_manipulator_id and changed it from every location. (https://discord.com/channels/731730685944922173/881073965047636018/1399272679952875632)
• Path tool overlays (specifically the three modes introduced in Add Pen and Path tool modes to avoid showing all handles #2264) were erroneously shown when there were duplicate layers, that has been fixed now by passing LayerNodeIdentifier along with the PointId for uniqueness of point.
• Flip Smooth Sharp had bloated code from previous implementation which used to check closest point and then change it to smooth or sharp, it was later changed to flipping for all selected points (Make the Path tool support multi-point conversion between smooth/sharp on double-click #2498)
• Flip smooth sharp didn't worked for points of other layers which are also in the selection (it does now).
• Vector mesh support for Ctrl + J join path feature, if vector mesh enabled, can join non terminal points also.

[4adex]

Week 13:

• Completed the separate segment and peel segment feature (Separate segments #3104)
• Fixed 3 regressions from the ⁠✅code-todo-list channel related to path and pen tool. (Fix history transaction issues in the Path tool #3111)